1. Field of the Invention
This invention relates to the production of rolled, rigid foams, particularly polyurethane and polyisocyanurate foams.
2. Description of the Prior Art
It is known to prepare foam laminates of the kind comprising a rigid layer of foam sandwiched between two skins. These foams, such as the polyurethanes and polyisocyanurates, have been very well accepted for many years because of their well-known advantages and widespread usefulness for structural, insulating and/or decorative purposes.
The rigid foams have excellent structural strength coupled with a relatively low density, and, in their sandwich-type constructions, their rigidity makes them particularly suitable for building purposes. Also, because of their generally closed cell, or substantially closed cell structure, they are superior heat insulators. The presence of the isocyanurate ring structure in the polyisocyanurate foams provides these foams with excellent high temperature properties, particularly an outstanding resistance to deformation at high temperatures.
Although these lightweight faced panels of the prior art are thus of considerable value as rigid and unbent insulating materials, this utilization leaves unaddressed the many areas where curved insulation is needed. If, for example, the highly insulating closed cell polyisocyanurate foams were available as rolled goods, the market for such foams could profitably expand to applications not currently exploited, such as pipe, tank and duct wrap. Furthermore, having such foams in a rolled form would contribute significantly to their manageability in use. A roll of foam would be much easier to transport and handle than the same amount of foam in the form of a number of discrete rigid panels.